Interesting thing about Phelps' stroke

I was watching a youtube multi-angle video of Phelps, and something really struck me. Aside from loping a bit, he had a half-catchup stroke on one side, but more of a rotary stroke on the other. It might be because he's breathing to the one side and takes extra time to get a good breath. I'm curious if any of you have similar asymmetry to your stroke. Here's the link, you'll see it best on the side view. www.youtube.com/watch